You mainly asked for diet info, right? Since you seem to be exercising already, start logging your daily food intake with a food diary (my girlfriend keeps hers on her kitchen counter so every food item she takes she marks it down) or if you're better with the electronic side of things, use any of the online food logs such as the poster above mentioned (fitday.com, mypyramid.gov, etc). Once you start seeing what you're eating in black and white, you'll start to really see your eating patterns and also your nutritional imbalances. From there, you'll most likely find that you'll know exactly what to cut out and where your intake needs improvement. Any one of us could say to "cut out sweets", or "eat salads", but the reality is when you're seeing your own eating patterns laid out in front of you, you'll most likely know EXACTLY what you need to eliminate from your diet.
The only other little tidbits I could add would be when you do find out what foods you need to cut out and also the amount of calories you need to drop daily from your diet, don't deprive yourself of anything in its entirety but rather make changes weekly. For instance: if you find out that you need to drop 500 calories from your daily intake and you see from your food diary that you're fairly consistent with eating 1Tbls butter on 2 slices of toast in the morning, two 16 oz sodas throughout the day, and you enjoy a bowl of ice cream at night with your favorite TV show, you can add up the calories for all of these things and see which of these things you could cut out week 1, and then switch to cutting out the other things for week two, and so on. I don't believe in deprivation unless you're so close to your goal weight or you're super lean already and really need to be strict to lose even .5 lb a week. I'm not advocating junk food at all, I'm just saying that most people have things that they don't want to do without, especially when they are things they are most likely to eat/drink again once they get to their goal weight. For me, it is sugar and cream with my coffee as well as chocolate chip cookies...

So far, I've been successful with just watching my intake of coffee each day to keep my calorie allowance in check and only indulge on CCC's every once in a while (usually once a month). Of course, I must mention that I eat pretty much on point with the food pyramid- all whole foods and I try my best to keep that all balanced.
If you learn to moderate your intake of food/drinks, you'll be better prepared to deal with it later.